Hallo, Mike McGonagle hat gesagt: // Mike McGonagle wrote:
Any select query on a database has the potential of returning a single row, or a billion. The point of this is that each row contains a different set of data, and the PD program would process them sequentially. Getting all the rows at once would be very cumbersome programming in sorting out the data. Being able to process each row by itself is a little bit less daunting. Also, if you only get one row at a time from the database, that would be a LOT of querying, and the amount of time for each query might slow the system quite a bit.
Working with smaller result sets is pretty standard with SQL databases. If some query is returning billions of data, the query is wrong. A very common idiom with SQL programming is to first do a "SELECT COUNT(*) FROM x WHERE y", and then go through the result set in smaller steps using LIMIT. A Google search result page is an example for this in action.
Ciao